Pathomechanics in lumbopelvic movement in professional golfers with limited hip internal rotation

Abstract

Limited range of hip motion may cause lumbopelvic movement faultiness during a golf swing. We investigated the kinematics of the lumbo–pelvic–hip complex in golfers with limited internal rotation of the hip during a golf swing. Of the 30 male professional golfers who participated in this study, 15 showed limited internal motion in the lead hip (LHIM; <20), whereas the other 15 participants had normal internal motion in the hip (NHIM; >30). The kinematics of the lumbar spine, pelvis, and hip were assessed using 3-dimensional motion analysis with 8 infrared cameras. Passive straight leg raise and Thomas test were performed to determine the lengths of the hamstring and iliopsoas muscles. Trunk muscle strength was tested using the Biodex System, and isometric hip rotator force for both legs was measured using a portable handheld dynamometer. A 2-tailed independent t-test was used to compare the mean differences in the kinematic parameters, trunk flexor/extensor strength, hip rotator strength, and hamstring flexibility between the 2 groups. Because iliopsoas flexibility data did not show normal distribution, Mann–Whitney test was used to compare the Thomas test values between the 2 groups. Correlation analysis was performed to identify the relationship between passive hip rotation range of motion (ROM) and maximum pelvis rotation angle during a golf swing. Statistical significance was set at p < 0.05. Golfers with LHIM had significantly shorter right-leg hamstrings (p = 0.000) and iliopsoas (p = 0.017) than did golfers with NHIM. Trunk strength was similar in the 2 groups. However, LHIM golfers exhibited less strength in the trail hip external rotator (p = 0.024) and lead hip internal rotator (p = 0.001) than the NHIM golfers. Kinematics showed that the lumbar rotation angle was significantly higher in LHIM golfers than in NHIM golfers at the top of backswing (p = 0.000), follow-through (p = 0.012), and finish phase (p = 0.020) of a golf-swing cycle. The lumbar right side bending angle was also significantly higher in LHIM than in NHIM golfers at the impact (p = 0.016) and finish phases (p = 0.003). Compared to golfers with NHIM, those with LHIM showed significantly high lumbar flexion angles (p = 0.000) at the address, top of backswing, acceleration, and impact phases. The range of pelvis rotation was significantly lower in LHIM than in NHIM golfers at the follow-through and finish phases (p = 0.000). The pelvis anterior tilt was significantly high in LHIM than in NHIM golfers at the top of backswing (p = 0.041); however, in the acceleration phase, golfers with LHIM had significantly greater posterior tilt of pelvis than the controls (p = 0.021). Golfers with LHIM had a significantly smaller left hip internal rotation angle than golfers with NHIM at the finish phase. Pearson’s correlation test revealed a positive relationship between the left hip internal rotation ROM and left pelvic rotation (r = 0.603; p = 0.000). On the contrary, left hip external rotation ROM was negatively correlated with the left pelvic rotation (r = -0.441). Our results suggest that professional golfers with limited internal hip rotation have hip rotator strength imbalance and muscle shortness (hamstring and iliopsoas) at the hips, which contributes to altered lumbopelvic movements and is a potential risk factor for low back pain.